Dr Matilda Dunn highlights significant concerns with the expansion of biogas production in Britain, countering the notion that biomethane is a straightforward solution to the country's gas supply issues. While Chris Huhne correctly points out that the UK faces a false choice between more North Sea drilling and increased reliance on gas imports, presenting biomethane as a simple answer overlooks serious environmental and health risks.
Environmental and Health Risks of Biogas Expansion
Biogas can reduce emissions when produced from waste. However, a growing share of feedstock for anaerobic digestion comes from purpose-grown energy crops. This increases pressure on land, competes with food production, and risks wider environmental harm.
Methane Leakage
The process is not leakage-free. Studies suggest that up to 13% of methane produced at anaerobic digestion sites can escape. Given methane's powerful warming effect, this is a significant issue. Current requirements for detecting and repairing leaks are not mandated or well enforced.
Air Quality and Ecosystem Damage
Expansion of biogas production also risks worsening air quality and damaging ecosystems. Ammonia emissions from the sector are rising, produced when nitrogen-rich feedstock is broken down in digesters. Ammonia contributes to the formation of particulate matter (PM2.5), a harmful air pollutant, and damages sensitive habitats.
Limited Contribution to Gas Demand
While biogas has a role to play in decarbonising the gas grid, it is no magic bullet. According to some estimates, it is unlikely to meet more than 18% of current gas demand. Without stronger safeguards, its expansion risks substituting one set of environmental problems for another.
